John Bowie's only living child begs to know what he did with her mother's body 40 years after disappearance

Roxlyn Bowie (left) was 31 when she disappeared from Walgett where she lived with her husband and two young children. (Supplied: NSW Police)

The only living child of John Bowie has pleaded with her father to reveal the truth of what he did with her mother's body.

Brenda Boyd, the daughter of Roxlyn and John Bowie, told the NSW Supreme Court that she often felt like "the angry little girl that lost her mum."